Ikkabar (also Iccobar) was a class M world near Federation space. Prior to the bombardment of the Iconian homeworld approximately 200,000 years ago, there was an Iconian outpost present on the planet. When the Iconian homeworld was attacked, Ikkabar, along with DiWahn and Dynassia, was one of the three worlds that the surviving Iconians escaped to via an Iconian Gateway.
Ikkabar initially appeared to be one of the most promising worlds of the three the Iconians escaped to, however the nature of the planet's orbit around its sun subjected it to extreme climate change. Even with the advanced technology the descendants of the survivors - called the Ikkabar - had at their hands, the extreme environmental conditions on the planet proved to be too much for the Ikkabar. Over the centuries the population had been reduced to roving tribes of hunter-gatherers, with their memories of Iconia becoming little more than a vague creation myth.
By the 24th century, Federation researchers visited Ikkabar, and it had become obvious that the Ikkabar were losing their struggle to survive on the planet. By 2355, the Ikkabar were virtually extinct, with only a single Ikkabar boy named Kanda Jiak surviving. That year the Federation sent the USS Clement to Ikkabar, and the crew rescued Jiak. (TNG novel The Devil's Heart and episode Contagion)
In 2365, Lieutenant Commander Data was able to use the Ikkabar language, plus the languages developed on DiWahn and Dynassia to help reconstruct the Iconian mother tongue. (TNG episode: "Contagion")